Most passenger-side SIRs have a housing mounted within a dashboard covered by a pop-open cover. Secured to the housing is a fabric envelope. Secured within the housing is an inflator. Typically, most passenger-side inflators are cylindrical in shape and are inserted within the housing through a side of the housing. When the inflator is ignited, the gas pressure within the housing exerts a pressure force within the housing which seeks to propel the inflator out of the housing. To secure the inflator during the ignition stages, three major techniques have been utilized.
A first inflator securing technique is shown in U.S. Pat. No. 5,364,123. In this design, an inflator has at its end a threaded stud which is secured by a nut to a first end of the housing. Although this arrangement works in a technically acceptable fashion, to ensure safety the torquing of the nut over the thread is monitored to be within a very small range of torque during the assembly operation. If for some reason the stud threads become stripped during installation, the entire inflator must be scrapped. The inflator has a very high economic content, and scrapping of an inflator is highly undesirable.
A second technique for securing the inflator within the housing is to provide a retainer which encircles the inflator. A series of set screws threaded along the length of the housing is provided to force the inflator against the retainer. The set screw method is shown in U.S. Pat. No. 5,340,147. Again, this technique provides a disadvantage of having to monitor the torquing of several screws along with the additional disadvantage of causing the screw to impinge upon the inflator. Care must be taken to ensure that the contact between the set screw and the inflator is not such that the inflator cylinder is damaged.
A third technique of retaining the inflator within the housing is almost a reverse of the set screw technique wherein an encircling retainer clamp is screwed down within the housing to act as a gigantic clamp around the inflator. It would be desirable to provide an SIR arrangement wherein the inflator may be assembled to the housing without the utilization of threaded fasteners.